The research proposed here is designed to contribute to an understanding of the morphological diversity of the primate craniofacial region. Functionally, the primate craniofacial region is dominated by the masticatory apparatus. This research will analyze the dissipation of masticatory forces throughout the primate face. This in vivo analysis of strain in the facila bones of Macacca mulatta will be accomplished using strain gauges. Rather than using single element strain gauges, rosettes (three strain gauge elements with a known orientation to one another) will be bonded directly to facial bones with isobutyl 2-cyanoacrylate. The restrained macaque will then bite or chew various types of food and bone strain will be recorded on multichannel chart recorder. In order to precisely correlate the animal's behavior with bone strain, the animal and the chart recorder will be videotaped. With a special effects generator, a split screen display of both animal and recorder will be produced and recorded.